WO2005073700A1

WO2005073700A1 - Liquid type identification device

Info

Publication number: WO2005073700A1
Application number: PCT/JP2005/000894
Authority: WO
Inventors: Toshiaki Kawanishi; Takayuki Takahata; Kiyoshi Yamagishi
Original assignee: Mitsui Mining & Smelting Co., Ltd.
Priority date: 2004-01-30
Filing date: 2005-01-25
Publication date: 2005-08-11
Also published as: EP1715330B1; EP1715330A4; US7493802B2; DE602005021313D1; US20070151331A1; EP1715330A1; JP3987041B2; JP2005214856A; ATE468530T1

Abstract

There is provided an identification device capable of accurately, rapidly, and easily identifying a hydrocarbon-based liquid and alcohol-based liquid. An identification sensor unit (2) is arranged to face a flow passage (20) of a liquid to be measured and includes an indirect heating type liquid type detection unit (21) having a heating body and a temperature-sensitive body, and a liquid temperature detecting unit (22) for detecting the temperature of the liquid to be measured. The identification sensor further includes an identification calculation unit for applying a single pulse voltage to the heating body of the liquid type detection unit (21) so as to generate heat and identifying the liquid to be measured according to an output of a liquid type detection circuit formed by the temperature-sensitive body of the liquid temperature detecting unit (21) and the liquid temperature detection unit. The identification calculation unit identifies the liquid to be measured according to a liquid-type-corresponding first voltage value corresponding to a difference between the initial temperature of the temperature-sensitive body when the heating body generates heat and a first temperature at the moment when a first time has elapsed from the start of application of the single pulse and a liquid-type-corresponding second voltage value corresponding to a difference between the initial temperature of the temperature-sensitive body and a second temperature at the moment when a second time longer than the first time has elapsed from the start of application of the single pulse.

Description

Specification

Liquid type identification device

Technical field

The present invention relates to a liquid type identification device that identifies the type of a liquid by using the thermal properties of the liquid.

Background art

[0002] In an internal combustion engine of an automobile, gasoline or light oil is generally used as fuel. These are mixtures of various hydrocarbons and other materials. However, since there is a possibility that the output of fossil fuels will decrease in the future and reduction of carbon dioxide emissions is required to prevent global warming, plant-based fuels in gasoline are used as fuel for internal combustion engines. It has been considered to mix alcohols such as ethanol or methanol.

[0003] The material composition of these fuels is determined according to the material composition and distilling conditions of crude oil, which is a raw material for gasoline and light oil, and the amount of alcohol added. Therefore, the characteristics of the combustion of these fuels vary depending on the material composition. Etc.) may not be optimal for other fuels

[0004] In order to improve the fuel efficiency by improving the output efficiency of an internal combustion engine and to reduce the amount of incomplete combustion products such as hydrocarbons (HC) and carbon monoxide (C〇) in exhaust gas, It is necessary to perform combustion by performing control such as mixing air at an ideal ratio (that is, optimizing the air-fuel ratio) according to the fuel actually supplied to the internal combustion engine.

[0005] In order to keep the material composition of the fuel constant and not to change the optimal combustion conditions, individual hydrocarbons such as pentane, cyclohexane, octane, etc., which are components of the fossil fuel, or individual alcohols such as methanol , Ethanol and the like are considered to be used as fuel, either alone or as a mixture of at most two types. This type of fuel is roughly divided into hydrocarbon fuel and alcohol fuel. [0006] Therefore, if such various fuels are used in parallel in the fuel tank, there is a risk that fuel other than the predetermined fuel may be erroneously supplied when refueling the fuel tank. is there. If the fuel supplied to the internal combustion engine is different from the prescribed one, the output efficiency of the engine may be extremely reduced, and such a situation must be avoided

[0007] For this reason, it is desirable that the type of fuel supplied from the fuel tank to the internal combustion engine is also actually detected on the vehicle side to confirm that the type is predetermined.

[0008] Further, when the detected fuel type is similar to a predetermined fuel type, it is desirable to optimize the combustion conditions of the internal combustion engine according to the detected fuel type. That is, the type of fuel actually supplied to the internal combustion engine is identified, and the combustion conditions of the internal combustion engine are appropriately set in accordance with the identification result. It is desirable to achieve a stable combustion state (ie, a combustion state that increases the output tonnolek of the internal combustion engine and reduces the amount of incomplete combustion products in the exhaust gas).

[0009] Since the combustion characteristics and the physical properties of hydrocarbon fuels and alcohol fuels are greatly different from each other, it is important to first determine to which of these the liquid to be measured (fuel) belongs. It is. Further, it is preferable to identify what kind of liquid to be measured (fuel) is a hydrocarbon fuel or an alcohol fuel.

[0010] As a method of identifying the type of fluid containing a liquid, for example, Japanese Unexamined Patent Publication No. 11-153561 (Patent Document 1) discloses a method in which a heating element is heated by energization, and a thermosensitive element is heated by this heat generation. A fluid identification method in which the fluid to be identified thermally influences the heat transfer from the heating element to the temperature-sensitive body, and the type of the fluid to be identified is determined based on the electrical output corresponding to the electrical resistance of the temperature-sensitive body. Further, there is disclosed an apparatus in which energization of a heating element is periodically performed.

Patent Document 1: Japanese Patent Application Laid-Open No. 11-153561 (in particular, paragraphs [0042] and [0049])

Problems to be solved by the invention

[0011] However, the fluid identification method described in Patent Document 1 can identify fluids having considerably different properties, such as water, air, and oil, using representative values, for example. Accurate and quick distinction between hydrocarbon liquid and alcohol liquid Cannot be done well enough.

[0012] In view of the above situation, the present invention provides an identification device that can accurately, quickly, and easily identify a hydrocarbon-based liquid and an alcohol-based liquid that can be used as fuel in particular. It is intended for that purpose.

[0013] Further, the present invention provides an identification device capable of accurately, quickly and easily identifying what kind of liquid to be measured is a hydrocarbon liquid or an alcohol liquid. The purpose is.

Means for solving the problem

According to the present invention, the above object is achieved by:

A liquid type identification device for identifying a liquid to be measured belonging to a hydrocarbon-based liquid or an alcohol-based liquid,

An identification sensor unit is provided facing the flow path of the liquid to be measured. The identification sensor unit includes an indirectly heated liquid type detection unit including a heating element and a temperature sensing element, and the liquid to be measured. And a liquid temperature detecting unit for detecting the temperature of the

A single pulse voltage is applied to the heating element of the indirectly heated liquid type detection unit to cause the heating element to generate heat, and includes a temperature sensing element of the indirectly heated liquid type detection unit and the liquid temperature detection unit. And a discriminating operation unit for discriminating the liquid to be measured based on the output of the liquid type detection circuit, wherein the discriminating operation unit determines the initial temperature of the thermosensitive element when the heat generating element generates heat. The first voltage value corresponding to the liquid type corresponding to the difference from the first temperature at the lapse of the first time from the start of the single pulse application, the initial temperature of the thermosensitive element, and the first temperature from the start of the single pulse application. A liquid type identification device, wherein the liquid to be measured is identified by a liquid type-corresponding second voltage value corresponding to a difference from a second temperature at a lapse of a second time longer than the second time.

Is provided.

[0015] In one embodiment of the present invention, the second time is an application time of the single pulse. In one embodiment of the present invention, the first time is 以下 or less of the application time of the single pulse. In one embodiment of the present invention, the first time is 0.5-1.5 seconds. In one embodiment of the present invention, the application time of the single pulse is 3 to 10 seconds.

In one embodiment of the present invention, the voltage value corresponding to the initial temperature of the temperature sensitive body A voltage value corresponding to the first temperature of the temperature sensing element is obtained by using an average initial voltage value obtained by sampling and averaging the initial voltage before the application of the single pulse to the heating element a predetermined number of times. As an average first voltage value obtained by sampling and averaging the first voltage at a lapse of a first time a predetermined number of times from the start of the single pulse application to the heating element, (2) As a voltage value corresponding to the temperature, an average second voltage value obtained by sampling a predetermined number of times of a second voltage after a lapse of a second time from the start of the single pulse application to the heating element and averaging the same is used. The difference between the average first voltage value and the average initial voltage value is used as the liquid type corresponding first voltage value, and the average second voltage value and the average initial voltage value are used as the liquid type corresponding second voltage value. The difference from the voltage value is used.

In one aspect of the present invention, a liquid temperature corresponding output value corresponding to the liquid temperature of the liquid to be measured is input from the liquid temperature detection unit to the identification calculation unit, and the identification calculation unit The liquid temperature correspondence obtained for the measurement target liquid to be identified is obtained using a calibration curve prepared based on the plurality of types of reference liquids to be measured and showing the relationship of the liquid type corresponding first voltage value to the liquid temperature. Based on the output value and the liquid type-corresponding first voltage value, it is determined whether the liquid to be measured is a hydrocarbon liquid or an alcohol liquid. In one embodiment of the present invention, a liquid temperature corresponding output value corresponding to the liquid temperature of the liquid to be measured is input from the liquid temperature detecting unit to the identification calculation unit, and the identification calculation unit includes a hydrocarbon-based liquid. Using a calibration curve created for a plurality of types of reference liquids to be measured, each of which is known for alcoholic liquids, and showing the relationship between the liquid temperature and the second voltage value corresponding to the liquid type, it can be obtained for the liquid to be identified. The liquid to be measured is identified based on the output value corresponding to the liquid temperature, the second voltage value corresponding to the liquid type, and the result of the determination.

[0018] In one embodiment of the present invention, the identification calculation unit includes a microcomputer. In one aspect of the present invention, the indirectly heated liquid type detection unit and the liquid temperature detection unit are respectively a heat transfer member for the liquid type detection unit and a heat transfer for the liquid temperature detection unit for heat exchange with the liquid to be measured. It has a member.

The invention's effect

[0019] According to the present invention, a single pulse voltage is applied to the heating element of the indirectly heated liquid type detection unit to cause the heating element to generate heat, and the identification calculation unit based on the output of the liquid type detection circuit, Said The liquid to be measured belonging to hydrocarbon liquid or alcohol liquid is identified based on the liquid type first voltage value and liquid type corresponding second voltage value when the heating element generates heat. And it can be easily identified.

[0020] In particular, an average initial voltage value is used as a voltage value corresponding to the initial temperature of the temperature sensing element, and the average first voltage value is used as a voltage value corresponding to the first temperature of the temperature sensing element, The average second voltage value is used as a voltage value corresponding to the second temperature of the thermosensitive body, and the difference between the average first voltage value and the average initial voltage value is used as the liquid type corresponding first voltage value, By using the difference between the average second voltage value and the average initial voltage value as the liquid type-corresponding second voltage value, more stable identification is possible.

[0021] Further, using a first calibration curve indicating the relationship between the liquid temperature and the liquid type-corresponding first voltage value, the liquid temperature-corresponding output value obtained for the liquid to be measured and the liquid type-corresponding first voltage value are used. A determination is made as to whether the liquid to be measured is a hydrocarbon-based liquid or an alcohol-based liquid based on the above, and the liquid type-corresponding second voltage value for the liquid temperature of each of the hydrocarbon-based liquid and the alcohol-based liquid Using the calibration curve indicating the relationship, the liquid to be measured is identified based on the output value corresponding to the liquid temperature obtained for the liquid to be measured, the second voltage value corresponding to the liquid type, and the result of the determination. By doing so, more accurate identification becomes possible. BEST MODE FOR CARRYING OUT THE INVENTION

Hereinafter, embodiments of the present invention will be described with reference to the drawings.

FIG. 1 is a schematic configuration diagram showing a use state of an embodiment of a liquid type identification device according to the present invention, and FIG. 24 is a partial cross-sectional view thereof. In the present embodiment, the measured liquid supply path supplies the measured liquid from the tank of the measured liquid (fuel) to the internal combustion engine. However, the measured liquid supply path of the present invention is not limited to this. For example, a path for supplying the liquid to be measured from a tank to a tank lorry, or a path for supplying the liquid to be measured from a large tank to a small tank may be used.

As shown in FIG. 1, a liquid type identification device 1 for identifying the type of the liquid to be measured is arranged in the course of supplying the liquid to be measured from the liquid tank T to the internal combustion engine E to the liquid to be measured. ing. The identification device 1 includes a measurement section 3, a first flow passage 4T having one end connected to a tank side portion (pipe) 14T, which is an upstream portion of the liquid supply path, by a pipe joint 8T, and a liquid to be measured. An internal combustion engine-side portion (pipe) 14E, which is a downstream portion of the supply path, includes a second flow passage 4E, one end of which is connected by a pipe joint 8E. The measuring section 3 has a liquid flow path 20 to be measured formed by the case substrate 2a and the case force bar 2b, and one end of the flow path (the lower end in FIGS. 13A and 13B) has the first flow path 4T. And the other end (the upper end in FIGS. 13 to 13) is connected to the other end of the second flow passage 4E.

The identification device of the present embodiment is connected to the measuring section 3 and a part of the first flow path 4T (that is, as shown in FIG. 1, connected to the tank side portion 14T of the liquid supply path to be measured). Part of the second flow passage 4E (that is, the part other than the end connected to the engine side part 14E of the liquid supply path to be measured as shown in FIG. 1). It has a housing 6 for housing. Further, the portion of the first flow passage 4T outside the housing 6 (that is, the end connected to the tank side portion 14T of the liquid supply path to be measured) is covered with a heat insulating coating material 4T1, and the second flow passage 4E The portion outside the housing 6 (that is, the end connected to the engine side portion 14E of the liquid supply path to be measured) is covered with the heat insulating coating 4E1.

In the housing 6, a circuit board 12 constituting a liquid type detection circuit described later is arranged. The circuit board 12 is provided with a microcomputer (microcomputer) constituting a discrimination calculation unit described later. Further, a wiring 13 for communication between the circuit board 12 and the outside is provided.

[0027] The interior space of the housing 6 (a part excluding the measurement unit 3, the first flow passage 4T, the second flow passage 4 ', the circuit board 12, and the like) is filled with a heat insulating material. As the heat insulating material and the heat insulating covering materials 4 1 and 4E1, for example, those made of rubber or foamed plastic can be used. By force, even if the first flow passage 4 通路 and the second flow passage 4Ε are made of metal, the presence of the heat insulating coverings 4T1, 4Τ1, the housing 6, and the heat insulating material inside the housing 6 The influence of the external temperature can be reduced, and the identification accuracy can be improved. When the housing 6 is not provided, it is preferable to apply a heat insulating coating to the entire first flow passage 4Τ and the second flow passage 4Ε.

[0028] The measuring unit 3 includes an identification sensor unit 2 disposed facing the liquid flow path 20 to be measured. The identification sensor section 2 has an indirectly heated liquid type detection section 21 including a heating element and a temperature sensing element, and a liquid temperature detection section 22 for measuring the temperature of the liquid to be measured. Indirectly heated liquid type detection unit 21 The liquid temperature detector 22 is arranged at a certain distance in the vertical direction. Fig. 5 shows a cross-sectional view of the indirectly heated liquid type detection unit 21.

As shown, the indirectly heated liquid type detection unit 21 and the liquid temperature detection unit 22 are integrated by a mold resin 23. As shown in FIG. 5, the indirectly heated liquid type detection unit 21 is composed of a thin film chip 21a including a heating element and a temperature sensing element, and a liquid joined by the thin film chip and a bonding material 2 lb. It has a metal fin 21c as a heat transfer member for the seed detection section, and external electrode terminals 21e electrically connected to electrodes of a heating element and a temperature sensing element of a thin film chip, respectively, by bonding wires 21d. The liquid temperature detecting section 22 has a similar configuration, and has a metal fin 22c and an external electrode terminal 22e as a heat transfer member for the liquid temperature detecting section.

FIG. 6 is an exploded perspective view of the thin film chip 21a of the indirectly heated liquid type detection unit 21. The thin film chip 2 la is composed of, for example, Al O force, a substrate 21al made of Ti, a temperature sensing element 21a2 made of Ti / Pt,

An inter-layer insulating film 21a3 consisting of 2 3 2, a heating element 21a4 consisting of TaSiO

2

The pole 21a5, the protective film 21a6 with SiO force, and the electrode pad 21a7 made of Ti / Au

2

It consists of what was laminated suitably. The temperature sensing element 21a2 is formed in a meandering pattern (not shown). The thin film chip 22a of the liquid temperature detecting section 22 has the same structure, but only the temperature sensing element 22a2 is operated without operating the heat generating element.

As shown in FIGS. 3 and 4, the indirectly heated liquid type detection unit 21 and the mold resin 23 of the liquid temperature detection unit 22 are attached to the case substrate 2 a of the measurement unit 3. The case substrate 2a is provided with a cover member 2d so as to pass through the fins 21c for the liquid type detection unit and the fins 22c for the liquid temperature detection unit. With this cover member, a liquid introduction passage 24 to be measured is formed which extends vertically in FIG. 13 through the liquid type detecting portion fins 21c and the liquid temperature detecting portion fins 22c and is open at both upper and lower ends. As shown in FIG. 4, when the cover member 2d is attached to the case substrate 2a, the flange portion of the mold resin 23 is pressed toward the case substrate 2a, whereby the mold resin 23 is displaced. It is fixed against.

[0032] The case substrate 2a, the case cover 2b, the cover member 2d, the first flow passage 4T, and the second flow passage 4E are made of a corrosion-resistant material such as stainless steel.

FIG. 7 shows a configuration of a circuit for identifying a liquid type in the present embodiment. The above-mentioned indirectly heated liquid A bridge circuit 68 is formed by the temperature sensing element 21a2 of the seed detection unit 21, the temperature sensing element 22a2 of the liquid temperature detection unit 22, and the two resistors 64 and 66. The output of the bridge circuit 68 is input to the differential amplifier 70, and the output of the differential amplifier (also referred to as the liquid type detection circuit output or sensor output) constitutes a discrimination calculation unit via an AZD converter not shown. Microcomputer (microcomputer) Input to 72. The microcomputer 72 receives a liquid temperature corresponding output value corresponding to the liquid temperature to be measured from the temperature sensing element 22a2 of the liquid temperature detecting section 22 via the liquid temperature detecting amplifier 71. On the other hand, the microcomputer 72 outputs a heater control signal for controlling the opening and closing of the switch 74 located on the power supply path to the heating element 21a4 of the indirectly heated liquid type detection unit 21.

Hereinafter, the liquid type identification operation in the present embodiment will be described.

When the liquid type is identified, supply of the liquid to be measured from the tank T to the engine E is stopped. That is, the liquid type identification is performed when the engine operation is stopped. The supply path of the liquid to be measured from the tank T to the engine E is always filled with the liquid to be measured, including the inside of the liquid flow path 20, the first flow path 4T, and the second flow path 4E of the identification device 1. are doing. Therefore, at the time of liquid type identification, the liquid to be measured in the liquid flow path 20 to be measured, including the liquid introduction path 24 to be measured, is not substantially forced to flow ideally.

When the switch 74 is closed for a predetermined time (for example, 3 to 10 seconds; 4 seconds in FIG. 8) by a heater control signal output from the microcomputer 72 to the switch 74, the predetermined height of the heating element 21a4 is raised. A single pulse voltage P (for example, 10 V) is applied to cause the heating element to generate heat. At this time, the output voltage (sensor output) Q of the differential amplifier 70 gradually increases during application of the voltage to the heating element 21a4, and gradually decreases after the voltage application to the heating element 21a4, as shown in FIG. I do.

As shown in FIG. 8, the microcomputer 72 samples the sensor output for a predetermined number of times (for example, 256 times) for a predetermined time (for example, 0.1 second) before the start of voltage application to the heating element 21a4. The average initial voltage value VI is obtained by calculating the average value. This average initial voltage value VI corresponds to the initial temperature of the thermosensitive body 21a2.

Further, as shown in FIG. 8, a first time (for example, 1Z2 or less of the application time of a single pulse, which is less than 0.1Z2, which is a relatively short time from the start of voltage application to the heating element). 5-1. 5 seconds; 1 second in Fig. 8) (Sensor output at the end of the first time) Is sampled a predetermined number of times (for example, 256 times), and an operation for taking the average value is performed to obtain an average first voltage value V2. This average first voltage value V2 corresponds to the first temperature at the time when the first time for applying a single pulse to the temperature sensing element 21a2 elapses. Then, a difference V01 (= V2-V1) between the average initial voltage value VI and the average first voltage value V2 is obtained as a liquid type-corresponding first voltage value.

Further, as shown in FIG. 8, a second time (for example, a single pulse application time; 4 seconds in FIG. 8) that is a relatively long time from the start of voltage application to the heating element has elapsed. At this time (specifically, immediately before the lapse of the second time), the sensor output is sampled a predetermined number of times (for example, 256 times), and an average is calculated to obtain an average second voltage value V3. This average second voltage value V3 corresponds to the second temperature when a second time has elapsed since the start of the single pulse application to the temperature sensing element 21a2. Then, a difference V02 (= V3-V1) between the average initial voltage value VI and the average second voltage value V3 is obtained as a liquid type-corresponding second voltage value.

By the way, part of the heat generated in the heating element 21a4 based on the voltage application of the single pulse as described above is transmitted to the temperature sensing element 21a2 via the liquid to be measured. There are two main forms of this heat transfer that differ depending on the time from the start of pulse application. That is, in the first stage within a relatively short time (eg, 1.5 seconds) from the start of pulse application, heat transfer is mainly conduction. On the other hand, in the second stage after the first stage, heat transfer is mainly dominated by natural convection. This is because in the second stage, natural convection occurs due to the liquid to be measured heated in the first stage, and the ratio of heat transfer thereby increases.

[0041] The heat transfer by conduction in the first stage greatly depends on the thermal conductivity of the liquid to be measured. The heat transfer by natural convection in the second stage greatly depends on the kinematic viscosity of the liquid to be measured. Some known liquids to be measured belonging to hydrocarbon liquids and alcohol liquids (cyclohexane, pentane, octane, toluene, o-xylene as hydrocarbon liquids, and methanol and ethanol as alcohol liquids) , Propanol), the first voltage value V01 (= V2-V1) corresponding to the liquid type obtained with the first time being 1.5 seconds in the apparatus of the present embodiment and the thermal conductivity of the liquid to be measured. Figure 9 shows the relationship. Further, for the same liquid to be measured, the second voltage value V 02 (= V3-V1) corresponding to the liquid type obtained by setting the second time to 5 seconds with the apparatus of the present embodiment and the kinematic viscosity of the liquid to be measured. Figure 10 shows the relationship.

[0042] From FIG. 9, there is a considerable correlation between the liquid type-corresponding first voltage value V01 and the thermal conductivity of the liquid to be measured. It can also be seen that the alcohol-based liquid is located in a region where the first voltage value V01 corresponding to the liquid type is smaller than the boundary value Vs, and the hydrocarbon-based liquid is located in a region larger than the boundary value Vs. Also, from FIG. 10, it can be seen that the liquid type-corresponding second voltage value V02 and the kinematic viscosity of the hydrocarbon-based liquid and the kinematic viscosity of the alcohol-based liquid have a considerable correlation independently of each other.

Therefore, in the present embodiment, the relationship between the temperature and the liquid type-corresponding first voltage value V01 for some known liquids to be measured (reference liquids to be measured) belonging to hydrocarbon liquids and alcohol liquids is described. The first calibration curve shown is obtained in advance, and this calibration curve is stored in the storage means of the microcomputer 72. An example of the first calibration curve is shown in FIG. In this example, a first calibration curve is created for reference liquids to be measured having thermal conductivity λ of λ 1 and λ 2.

As shown in FIG. 11, since the liquid type-corresponding first voltage value V01 depends on the temperature, the type of the liquid to be measured (here, the liquid In the identification by the first voltage value νοι, the type of the liquid to be measured is specified by the thermal conductivity; I) when identifying the liquid temperature from the temperature sensing element 22a2 of the liquid temperature detection unit 22. The output value T corresponding to the liquid temperature input through the amplifier 71 is also used. FIG. 12 shows an example of the output value T corresponding to the liquid temperature. Such a calibration curve is also stored in the storage means of the microcomputer 72.

At the time of measurement, first, a temperature value is obtained from the liquid temperature corresponding output value T obtained for the liquid to be measured, using the calibration curve of FIG. Based on the obtained temperature values, next, in the first calibration curve of FIG. 11, the first voltage values V01 (λ 1; t), V01 (^) corresponding to the liquid type of each calibration curve corresponding to the temperature value t. 2; t). Then, λχ of the liquid type corresponding first voltage value V01 (λχ; ΐ) obtained for the liquid to be measured is converted to the liquid type corresponding first voltage value V01 (λ1; ΐ), V0l (2 ; t) to determine. That is, based on λχ «, ν01 (λχ; ΐ), V01 (λ l; t), V01 (^ 2; t),

(λ2_λ 1) [V01 (x; t) — ν01 (λ l; t)]

/ [ν01 (λ2; ί) -ν01 (λ l; t)]

Ask for power. As described above, the liquid type can be accurately and quickly (instantly) identified. Note that by using the liquid temperature-dependent output value T instead of the temperature as the first calibration curve in Fig. 11, the storage of the calibration curve in Fig. 12 and the conversion using this can also be omitted. The

As can be seen from FIG. 9, the liquid to be measured is determined by determining the magnitude relationship between the obtained liquid type-corresponding first voltage value V01 and the boundary value Vs to determine whether the liquid to be measured is a hydrocarbon liquid or an alcohol liquid. It is possible to determine to which of these the two belong.

On the other hand, in the present embodiment, for each of the hydrocarbon-based liquid and the alcohol-based liquid, the relationship between the temperature and the liquid type-corresponding second voltage value V02 for some liquids to be measured (reference liquids to be measured). Is obtained in advance, and this calibration curve is stored in the storage means of the microcomputer 72. Figures 13 and 14 show examples of the second calibration curve. FIG. 13 relates to a hydrocarbon-based liquid. In this example, a second calibration curve is created for reference liquids having kinematic viscosities V of V1 and V2. FIG. 14 relates to an alcohol-based liquid. In this example, a second calibration curve is created for reference liquids having kinematic viscosities V of V3 and V4. When it is determined that the liquid to be measured is a hydrocarbon liquid by the above-described identification using the first voltage value corresponding to the liquid type V01, the second calibration curve in FIG. 13 is used in the following identification. If the liquid to be measured is determined to be an alcohol-based liquid by the above-described identification using the liquid type-corresponding first voltage value V01, the following calibration in FIG. Use lines.

As shown in FIG. 13 and FIG. 14, since the liquid type-corresponding second voltage value V02 depends on the temperature, the type of the liquid to be measured (here In the identification by the liquid type-corresponding second voltage value V02, the type of the liquid to be measured is specified by the kinematic viscosity V). The above-mentioned liquid temperature corresponding output value T input via the detection amplifier 71 is also used.

At the time of measurement, first, a temperature value is obtained from the output value T corresponding to the liquid temperature to be measured using the calibration curve in FIG. Let the obtained temperature value be t, and then, in the second calibration curve of FIG. 13 or FIG. 14, the liquid type-corresponding second voltage value V02 (vl; t) of each calibration curve corresponding to the temperature value t V02 (v2; t) or V02 (v3; t), V02 (v4; t) is obtained. Then, VX of the liquid type corresponding second voltage value V02 x; t) obtained for the liquid to be measured is converted to the liquid type corresponding second voltage value V02 (V l; t), V02 ( V2; t) or V02 (v3; t) and V02 (v4; t) are determined by performing a proportional operation. That is, vx «, V01 (vx; t), V02 (V l; t), V02 (v 2; t) or (vx; t), V02 (v3; t), V02 (v4; t)

v x = 1 +

(v 2-v 1) [V02 (vx; t) -V02 (v l; t)]

/ [V02 (v2; t) -V02 (vl; t)]

Or

v x = 3 +

(v 4-v 3) [V02 (vx; t) -V02 (v 3; t)]

/ [V02 (v4; t) -V02 (v3; t)]

Ask for power. As described above, the liquid type can be accurately and quickly (instantly) identified. Note that by using the liquid temperature corresponding output value T instead of the temperature as the second calibration curve in FIGS. 13 and 14, the storage of the calibration curve in FIG. 12 and the conversion using the same are omitted. Talk about things.

A signal indicating the value of the liquid type (thermal conductivity λ or kinematic viscosity V) obtained as described above is output via a D / A converter (not shown) to the output buffer circuit 76 shown in FIG. This is output as an analog output to the main computer (ECU), which controls combustion of the engine of the automobile (not shown). The analog output voltage value corresponding to the liquid temperature is also output to the main computer (ECU). On the other hand, the signals indicating the liquid type value and the liquid temperature value can be taken out as digital output as required, and can be input to a device that performs display, alarm, and other operations.

In order to improve the accuracy of the liquid type identification as described above, the liquid to be measured around the liquid type detection unit fins 21c and the liquid temperature detection unit fins 22c is required to be as strong as possible based on external factors. From the viewpoint that it is preferable to suppress the flow, it is preferable to use a cover member 2d, particularly one having a vertical liquid introduction path to be measured. Note that the cover member 2d also functions as a protection member for preventing contact of foreign matter.

[0052] The cover member 2d further improves the accuracy of liquid type identification when the inclination angle of the measuring unit 3, especially the identification sensor unit 2 with respect to the vertical direction changes, and when the cover member does not exist. It also has the function of improving. That is, if the cover member does not exist, The change in the form in which the heat generated from the heating element is transmitted to the thermosensitive body by the natural convection is large in response to the change in the temperature, the change in the second voltage value V02 corresponding to the liquid type of the same liquid to be measured is large. For this reason, the tilt angle range that does not cause confusion with the output value in the case of another type of liquid to be measured is relatively narrow. On the other hand, when the cover member 2d is present, the change in the form in which the heat generated from the heating element is transmitted to the temperature sensing element by the natural convection with respect to the change in the inclination angle is small (ie, Natural convection is always mainly generated along the liquid introduction path in the cover member 2d). Therefore, the change of the second voltage value V02 corresponding to the liquid type of the same liquid to be measured is small. The tilt angle range that does not cause confusion with the output value of the liquid to be measured is relatively wide.

In the above embodiments, the fuel to be supplied to the internal combustion engine is used as the fluid to be measured. However, in the present invention, the fluid to be measured is a hydrocarbon-based liquid or an alcohol-based liquid in another form. You can. Examples of such a form include a sample form for quality control of a petroleum plant or for analysis of hydrocarbon liquid and alcohol liquid in the environment. Further, the present invention can also be used as an apparatus for measuring the thermal conductivity and the kinematic viscosity of a hydrocarbon-based liquid and an alcohol-based liquid sample.

Brief Description of Drawings

FIG. 1 is a schematic configuration diagram showing a use state of an embodiment of a liquid type identification device according to the present invention.

FIG. 2 is a partial cross-sectional view of the liquid type identification device of FIG. 1.

FIG. 3 is a partial cross-sectional view of the liquid type identification device of FIG. 1.

FIG. 4 is a partial cross-sectional view of the liquid type identification device of FIG. 1.

FIG. 5 is a sectional view of an indirectly heated liquid type detection unit.

FIG. 6 is an exploded perspective view of a thin film chip of the indirectly heated liquid type detection unit.

FIG. 7 is a configuration diagram of a circuit for identifying a liquid type.

FIG. 8 is a diagram showing a relationship between a single pulse voltage P applied to a heating element and a sensor output Q.

FIG. 9 is a diagram showing a relationship between a liquid type-corresponding first voltage value V01 and the thermal conductivity of the liquid to be measured.

FIG. 10 is a diagram showing the relationship between the liquid type-corresponding second voltage value V02 and the kinematic viscosity of the liquid to be measured. Garden 11] is a diagram showing an example of a first calibration curve.

Fig. 12 is a diagram showing an example of a liquid temperature corresponding output value T. Garden 13] is a diagram showing an example of a second calibration curve.

Garden 14] is a diagram showing an example of a second calibration curve.

Explanation of symbols

1 Identification device

2 Identification sensor

2a Case board

2b case cover

2d cover member

21 Indirectly heated liquid type detector

22 Liquid temperature detector

23 Mold resin

24 Liquid passage for measurement

21a Thin film chip

21b bonding material

21c, 22c metal fin

21d bonding wire

21e, 22e External electrode terminal

21al substrate

21a2, 22a2 Thermocouple

21a3 Interlayer insulating film

21a4 Heating element

21a5 Heating element electrode

21a6 Protective film

21a7 Electrode pad

3 Measurement section

4T 1st passage 4E 2nd passage

4T1, 4E1 Insulation coating

6 Housing

8T, 8E fittings

12 Circuit board

13 Wiring

14T Tank side of liquid supply path to be measured

14E Internal combustion engine side of liquid supply path to be measured

20 Flow path of liquid to be measured

64, 66 resistor

68 bridge circuit

70 Differential amplifier

71 Liquid temperature detection amplifier

72 Microcomputer

74 switches

76 Output buffer circuit

T tank

E internal combustion engine

Claims

The scope of the claims

[1] A liquid type identification device for identifying a liquid to be measured belonging to a hydrocarbon liquid or an alcohol liquid,

A single pulse voltage is applied to the heating element of the indirectly heated liquid type detection unit to cause the heating element to generate heat, and includes a temperature sensing element of the indirectly heated liquid type detection unit and the liquid temperature detection unit. And a discrimination calculation unit for discriminating the liquid to be measured based on the output of the liquid type detection circuit comprising

The discrimination calculation unit is configured to calculate a liquid type corresponding to a difference between an initial temperature of the thermosensitive body and an i-th temperature after an i-th time has elapsed from the start of the single pulse application when the heating element generates heat. Corresponding second liquid type corresponding to the difference between the voltage value and the initial temperature of the temperature sensing element and the second temperature after the second time longer than the first time from the start of the single pulse application. (2) A liquid type identification device that identifies the liquid to be measured based on two voltage values.

[2] The liquid type identification device according to claim 1, wherein the second time is an application time of the single pulse.

3. The liquid type identification device according to claim 1, wherein the first time is 1Z2 or less of the application time of the single pulse.

[4] The liquid type identification device according to claim 1, wherein the first time is 0.5 to 1.5 seconds.

[5] The liquid type identification device according to claim 1, wherein the application time of the single pulse is 310 seconds.

[6] An average initial voltage value obtained by sampling a predetermined number of times and averaging the initial voltage before the start of the single pulse application to the heating element as a voltage value corresponding to the initial temperature of the temperature sensing element. And sampling the first voltage after a lapse of a first time from the start of the single pulse application to the heating element a predetermined number of times as a voltage value corresponding to a first temperature of the temperature sensing element and averaging the first voltage. Using the averaged first voltage value obtained as the voltage value corresponding to the second temperature of the temperature sensing element from the start of the single pulse application to the heating element. Using the average second voltage value obtained by sampling and averaging the second voltage after the second time a predetermined number of times, the average first voltage value and the average value as the liquid type corresponding first voltage value are used. The liquid type according to claim 1, wherein a difference between the average second voltage value and the average initial voltage value is used as the liquid type-corresponding second voltage value using a difference from the average initial voltage value. Identification device.

[7] A liquid temperature corresponding output value corresponding to the liquid temperature of the liquid to be measured is input from the liquid temperature detection unit to the identification calculation unit, and the identification calculation unit outputs a plurality of known types of reference measurement liquids. The output value corresponding to the liquid temperature and the first voltage value corresponding to the liquid type obtained for the measurement target liquid to be identified are obtained using a calibration curve created for the body and indicating the relationship between the liquid type corresponding first voltage value and the liquid temperature. 2. The liquid type identification device according to claim 1, wherein a determination is made as to whether the liquid to be measured is a hydrocarbon-based liquid or an alcohol-based liquid.

[8] A liquid temperature corresponding output value corresponding to the liquid temperature of the liquid to be measured is input from the liquid temperature detecting unit to the discrimination calculation unit, and the discrimination calculation unit calculates a hydrocarbon-based liquid and an alcohol-based liquid respectively. Using a calibration curve created for a plurality of known types of reference liquids to be measured and showing the relationship between the liquid temperature and the liquid-type-corresponding second voltage value, the liquid temperature-corresponding output value obtained for the liquid to be identified as the measurement target 8. The liquid type identification apparatus according to claim 7, wherein the liquid to be measured is identified based on the liquid type corresponding second voltage value and the result of the determination.

[9] The liquid type identification device according to claim 1, wherein the identification calculation unit includes a microcomputer.

[10] The indirectly heated liquid type detection unit and the liquid temperature detection unit include a liquid type detection unit heat transfer member and a liquid temperature detection unit heat transfer member for heat exchange with the liquid to be measured. The liquid type identification device according to claim 1, wherein: